Strategies for prevention and control of rotavirus-induced disease must be based upon a detailed knowledge of the virus, the virus host-cell interactions, the mechanism of virus replication, the origin, characteristics and function of the specific viral proteins, and the role of those proteins in infection and immunity. The proposed study which is designed to enhance the basic understanding of some of these parameters focuses on three basic areas of research using the simian rotavirus model. (1) A coding assignment map for the polypeptides encoded by each RNA segment will be constructed by in vitro translation of isolated rotavirus transcripts synthesized by the endogenous viral RNA polymerase. The primary gene products will be characterized as structural or nonstructural by immunoprecipitation with specific antisera, and by comparison of tryptic peptide maps of the in vitro synthesized polypeptides with those obtained from authentic viral structural polypeptides. (2) The biologic functions of specific structural polypeptides will be characterized with initial emphasis on the outer capsid proteins. Monospecific antisera prepared against individual rotavirus polypeptides will be used in combination with biological assays, immunoprecipitation experiments or direct purification methods to identify the polypeptides responsible for hemagglutination, neutralization and infectivity. The type common antigens will be identified by comparative studies utilizing heterologous (bovine, porcine, human) rotavirus strains. (3) The role of polypeptide modification on rotavirus synthesis, structure and function will be examined by analysis of the kinetics of rotavirus polypeptide and particle synthesis in infected cells. The role of post-translational polypeptide cleavage and glycosylation in the synthesis and biological function(s) of rotavirus particles will also be examined by the use of specific protease and glycosylation inhibitors. Derivation of a coding assignment map of the rotavirus genome in conjunction with the knowledge of the biologic functions of the viral polypeptides will lay the foundation to determine whether a relationship between RNA electropherograms and serological specificity can be established. Such knowledge could allow rapid determination of the number of rotavirus serotypes that exist and their distribution in nature. Knowledge of the origin, characteristics and functions of rotavirus specific proteins is essential for the eventual development and evaluation of effective methods for the prevention and control of this important disease in children and animals.